JPH0685734U - Heavy nut removal device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a heavy nut attachment / detachment device that can remove and attach a heavy lower nut safely and efficiently by a single operation without using a crane. [Structure] A post 10 that can be expanded and contracted in the vertical direction by the operation of a telescopic operation cylinder 15, and a hook pin 23 that can be inserted into the upper part of the center through hole of a large diameter double tightening bolt are provided at the tip, and the post 10 is located in the vicinity of a bolt to be removed A post suspension arm 20 for vertically suspending the post 10 and a moment stopper 26 which is provided at an intermediate position in the height direction of the post 10 and holds the post 10 in a vertical suspension posture.
A swivel column 30 fixed to the lower end of the telescopic actuating tube 12 of the post 10, a telescopic column 33 fitted and held in the swivel column so as to be able to move forward and backward, and an end face groove of the lower nut. A nut attachment that has a detachable engagement projection 37 and is rotatably supported by the tip of the telescopic column 33.
35 and.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a heavy nut attachment / detachment device used, for example, in periodic inspection work on a steam turbine.

[0002]

[Prior art]

 The high-pressure casing of a steam turbine installed in a thermal power plant, a nuclear power plant, a private power plant, etc. has horizontal flanges Fa and Fb (the plane of which is in the shape of a track) with a large-diameter double tightening bolt 1. The upper nut 2 and the lower nut 3 which are screwed to the upper and lower threaded portions of each of the bolts 1 are tightly coupled as shown in Fig. 5, and are used for the periodic inspection work of the steam turbine.・ It is necessary to remove and install nuts 2 and 3.

The maximum weight of the tightening bolts (large diameter double tightening bolts 1) for the horizontal flanges Fa and Fb of the high-pressure casing is 60 kg, so the nuts must be removed and installed. Although the lower nut 3 is used, since this nut is heavy and it is dangerous to support it by hand, a nut lifting tool as shown in FIG. 5 is used.

This conventional nut hoisting tool uses the center through hole 1a of the bolt 1 to pass the chain 4 through the bolt center through hole 1a, and the lower nut 3 at the lower end of the chain 4. The supporting disc 5 is attached, and the upper end handle 6 of the chain 4 is supported by a hand or a hoist to remove and attach the lower nut 3.

The chain 4 and the disc 5 are connected by inserting a chain connecting mandrel 7 into the disc center hole and fixing it with a thumbscrew 8, and between the disc 5 and the mandrel 7. A rolling bearing (not shown) is provided to prevent loosening of the thumbscrew 8 and twisting of the chain 4 when the lower nut 3 is turned.

Further, the plurality of nut receiving pins 9 removably engaged with the end surface grooves 3 a of the lower nut 3 are not shown so that the pin projecting length can be adjusted according to the outer diameter of the nut 3. It is fixed to the disk 5 with a set screw.

[0007]

[Problems to be solved by the device]

 The above-mentioned conventional nut hoisting tool requires the use of an overhead crane such as a hoist when removing / installing a heavy lower nut 3 (for example, a nut having a size of 6 inches or more). There is a problem that the crane cannot be used for work, and the work of removing and installing the nut 3 is a vertical work, so if the crane operator and the nut removal worker do not breathe properly, their hands may get caught and the chain 4 may There was a danger that it would come off the disc 5 or the chain 4 would break and the nut 3 would fall.

The present invention has been devised in order to solve the above-mentioned conventional problems, and its purpose is to safely and efficiently perform the removal and installation of a heavy lower nut by a single operation without using a crane. (EN) Provided is a weight nut attaching / detaching device.

[0009]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the weight nut attaching / detaching device of the present invention comprises a plurality of large diameter double tightening bolts 1 each having a horizontal through hole 1a in a horizontal flange Fa, Fb of an object to be fastened. When repairing and inspecting equipment that is fastened and connected with the upper nut 2 and the lower nut 3 that are heavy in weight and screwed to the upper and lower threaded portions of the tightening bolt 1, the nut lowering and attaching work of the bolt 1 is dangerous. The nut 3 is used for removing work and mounting work, and has a retractable operating cylinder 15 built therein, which is capable of expanding and contracting in the vertical direction by the operation of the cylinder, and is inserted into the upper portion of the center through hole 1a of the bolt 1. A post-hanging arm 20 which has a hook pin 23 at its tip and which is attached to the upper end of the post 10 and vertically hangs the post in the vicinity of a bolt to be detached, and a height direction of the post 10. A moment stopper 26, which is provided at an intermediate position and contacts the outer peripheral end surface of the flange Fa to maintain the vertical suspension posture of the post 10, and a swivel fixed to the lower end of the telescopic operation tube 12 of the post 10. The column 30 and an extension / contraction column 33 that is inserted and held in the swivel column so as to be able to move back and forth in the horizontal direction, and an engagement protrusion 37 that can be engaged with and disengaged from the end surface groove 3a of the lower nut 3 are provided. A nut attachment 35 rotatably supported at the tip of 33 is provided.

[0010]

[Action]

 In the weight nut attaching / detaching device having the above-mentioned configuration, the tip hook pin 23 of the post suspension arm 20 is inserted into the upper portion of the bolt center through hole 1a to vertically suspend the post 10 at a position near the bolt to be detached (this post). The vertical suspension posture of 10 is used in a set state in which it is held by a moment stopper 26 that abuts the outer peripheral end surface of the flange at the front end). By operating the ram 33, the nut attachment 35 is projectingly engaged with the end surface groove 3a of the lower nut 3 from below, and the lower nut 3 is loosened by rotating the nut attachment 35 with an impact wrench or the like. It can be safely removed from the bolt 1, and the bolt 1 can be removed by performing the reverse operation of removing the nut. It can be performed with high safety and efficiency of mounting of the lower nut 3 against.

[0011]

【Example】

 An embodiment of the present invention will be specifically described below with reference to the drawings. The heavy nut removing / attaching device in this embodiment includes a plurality of large-diameter double tightening bolts 1 having horizontal through holes 1a in the horizontal flanges Fa and Fb of a high-pressure casing, and upper and lower screw portions of the respective double tightening bolts 1. When repairing and inspecting a steam turbine that is fastened with the heavy upper nut 2 and lower nut 3, the nut of the bolt 1 is used for removing and installing the lower nut 3, which is dangerous to attach and detach. The post 10 is capable of expanding and contracting in the vertical direction, a post suspension arm 20 for vertically suspending the post 10 at a position near the detachable bolt 1, and a vertical suspension posture of the post 10. A moment stopper 26 for holding the post, a swivel column 30 and a telescopic column 33 at the lower end of the post, and a tip end of the telescopic column 33 that is rotatably supported by a shaft. It consists of door attachment 35..

More specifically, the post 10 has an outer tube 11 having a fixed arm stopper 13 and a detachable upper end arm stopper 14 and a telescopic operating cylinder 15 incorporated therein, and a slide inside the outer tube 11. The expansion / contraction operation tube 12 as an inner tube that is freely inserted and expanded / contracted by the cylinder 15, and the cap-shaped stopper 14 is fitted to the upper end of the post outer tube 11 as shown in FIG. The stopper bolt 14a shown in FIG. 2 and FIG.

The telescopic working cylinder 15 built in the outer tube 11 of the post 10 is an air cylinder with a lock brake 16 in the present embodiment, and is a control box 17 capable of adjusting the air pressure (see FIG. 4). ) Is operated so that a heavy nut (lower nut 3 having a large weight) of 3 inches to 7 inches can be vertically moved and stopped at an arbitrary position. The cylinder 15 has an air intake valve 18a and an exhaust valve 18b, and the lock brake 16 has a three-way valve 19 protruding to a lower position of the air intake valve 18a.

The post-suspension arm 20 has a base end portion fitted to the upper end portion (between the arm stoppers 13 and 14) of the post outer tube 11 so that the post suspension arm 20 can be expanded in a V shape (planar V shape) as shown in FIG. It is composed of a pair of right and left open / close rotary arms 21 and 22 that are attached together, and at the tip of each of the open / close rotary arms 21 and 22, a bolt center through hole 1a (adjacent bolts 1 located on both sides of the bolt 1 to be detached and attached) A hook pin 23, which can be inserted as shown in FIG. The hook pin 23 is fixed to the ends of the arms 21 and 22 by a quick nutter 24 and a stopper nut 25 as shown in FIG.

The moment stopper 26 is provided with a post holding fixture 27 (a holding fixture 29 which is fastened and fixed by two fastening screws 28 at an intermediate position in the height direction of the post outer tube 11). ) Is composed of two adjusting screws 26a, 26b having a long length which are screwed into the screw holes 27a, 27b on both sides, and the adjusting screws 26a, 26b are brought into abutting contact with the outer peripheral end face of the flange Fa as shown in FIG. Thus, the vertical suspension posture of the post 10 can be maintained.

The swivel column 30 is provided with a rectangular tube 31 having both ends opened, and a rectangular tube 31 protruding from the central portion of the upper surface of the rectangular tube 31 and horizontally attached to the lower end of the post telescopic operation tube 12 as shown in FIG. The rectangular tube 31 is provided with a clamp lever 34 for fixing the telescopic column 33, which is inserted so as to be able to move back and forth in the horizontal direction, to a desired position. .

The nut attachment 35 is integrally provided with a radial engagement projection 37 that can be engaged with and disengaged from the radial end surface groove 3 a of the lower nut 3 on the upper surface of a disc 36 that supports the lower nut 3. At the center of the lower surface of the plate 36, a rotary operation shaft 39 pivotally supported as shown in FIG. 1 is provided on the tip fitting sleeve 38 of the telescopic column 33, and the rotary operation shaft 39 is set in the shaft hole 39a. It is configured so that the nut 3 can be loosened or tightened by turning it (not shown). It can support a weight nut of 3 inches to 7 inches, and can rotate a large or small number of nuts. An attachment 35 is prepared (see FIG. 2).

Next, a preparatory work for using the weight nut attachment / detachment device having the above-described configuration, and a procedure for removing and attaching the lower nut 3 using the device will be described. (1) Preparation work a. At the work place, attach the post suspension arm 20 (a pair of left and right rotating arms 21, 22) to the post 10. b. Spread the two arms 21 and 22 to the left and right to form a V-shape and hook pins 23 at the tip of each arm to the upper part of the center through hole 1a of the adjacent bolt 1'located on both sides of the bolt 1 to be detached. Insert and set as in 4. c. A moment stopper 26 (adjustment screws 26a, 26b) is attached to the post 10, and the adjustment screws 26a, 26b are adjusted so as to abut on the outer peripheral end surface of the flange Fa as shown in FIG. Be able to maintain the hanging posture. d. The telescopic column 33 is inserted into the swivel column 30, and the nut attachment 35 is attached to the tip of the telescopic column 33. e. The control box 17 is connected to the cylinder air intake valve 18a, the exhaust valve 18b, and the lock brake three-way valve 19 of the post 10 by a tube.

F. Connect the power supply to the control box 17. (2) Nut removal procedure a. By operating the control box 17 and adjusting the cylinder pressure, the swiveling column 30, the telescopic column 33 at the lower end of the post, and the nut attachment 35 at the tip of the telescopic column are lowered to the lowest position. b. By operating the swivel column 30 and the telescopic column 33, the nut attachment 35 is moved below the lower nut 3 of the bolt 1 to be attached / detached. c. The pressure of the telescopic operation cylinder 15 is raised to raise the nut attachment 35 so that the engaging projection 37 is engaged with the end surface groove 3a of the lower nut 3. d. The telescopic column 33 is fixed by the clamp lever 34. e. Loosen the lower nut 3 by rotating the nut attachment 35 with an impact wrench. Immediately before the nut 3 comes off the bolt 1, the cylinder pressure is adjusted to be higher than the nut descending pressure. f. When the lower nut 3 is disengaged from the bolt 1, lower the cylinder pressure below the nut lowering pressure to lower the lower nut 3. g. While the nut is descending, press the cylinder brake switch on the control box 17 to brake the cylinder 15 and stop it at an arbitrary position. h. After the stop, the fixing of the telescopic column 33 is released by operating the clamp lever 34.

I. The swivel column 30 and the telescopic column 33 are operated and moved to the position where the nut 3 is lowered, and the nut 3 is manually lowered from the nut attachment 35. j. The swing column 30 and the telescopic column 33 are returned to their original positions, and the entire apparatus is manually moved to the next nut removal position in the assembled state as shown in FIG. 3, and the nut removal work similar to the above is performed. (3) Nut installation procedure a. By operating the control box 17 and adjusting the cylinder pressure, the swiveling column 30, the telescopic column 33 at the lower end of the post, and the nut attachment 35 at the tip of the telescopic column are lowered to the lowest position. b. The nut 3 is placed and engaged on the nut attachment 35. c. The swivel column 30 and the telescopic column 33 are operated to move the nut 3 placed on the nut attachment 35 under the bolt 1 to be attached. d. The telescopic column 33 is fixed by the clamp lever 34. e. The pressure of the telescopic operation cylinder 15 is raised, the nut attachment 35 is raised, and the nut 3 is set at the lower end of the bolt. f. Turn the nut attachment 35 manually to engage the nut 1 with the bolt 1 about one ridge, and turn the impact wrench to tighten the nut 3. g. The cylinder pressure is reduced to lower the nut attachment 35. h. After the stop, the fixing of the telescopic column 33 is released by operating the clamp lever 34.

I. The turning column 30 and the telescopic column 33 are returned to their original positions, and the entire apparatus is manually moved to the next nut mounting position in the assembled state as shown in FIG. 3, and the nut mounting work similar to the above is performed.

[0022]

[Effect of device]

 Since the weight nut attaching / detaching device of the present invention has the construction described in the scope of claim for utility model (Claim 1), the heavy nut lower nut can be removed and installed independently of the crane. Work can be done safely and efficiently.

According to the weight nut attaching / detaching device of the second aspect, the control box can be kept at hand, the device can be operated while checking the state of the nut, and the nut attachment can be replaced. It is possible to work from 3 inches to 7 inches with a single machine, and it is possible to perform independent work without the need for an overhead crane.

As a result, there is no need for vertical work as in the prior art, there is no risk of being caught by a hand or dropping the nut, and the safety and work efficiency in the work of removing and mounting the heavy nut are greatly improved. Also, if the structure of the bolt is basically the same, any manufacturer's equipment (for example, a high-pressure casing of a steam turbine) can work with the heavy nut desorption device of the present invention. It is possible.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of an assembled state showing a weight nut attaching / detaching device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the weight nut attaching / detaching device of the present invention in an exploded state.

FIG. 3 is a perspective view showing the weight nut attaching / detaching device of the present invention in an assembled state.

FIG. 4 is a side view showing the weight nut attaching / detaching device of the present invention in use.

FIG. 5 is a cross-sectional view showing a conventional nut lifting tool in a state where the nut is detached and attached.

[Explanation of symbols]

Fa, Fb ... Horizontal flange of adherend, 1 ... Large diameter double tightening bolt, 1a ... Center through hole of the bolt, 2 ... Upper nut,
3 ... Lower nut, 3a ... End nut groove of lower nut, 10 ... Telescopic post, 11 ... Post outer tube, 12 ... Telescopic operating tube, 15
… Expansion and contraction cylinders, 16… Lock brakes, 17… Control box, 20… Post suspension arms 21,
22 ... a pair of left and right rotating arms, 23 ... hook pins,
26 ... Moment stopper, 27 ... Post-wrapping fixed body,
30 ... Revolving column, 33 ... Telescopic column, 34 ... Clamp lever, 35 ... Nut attachment, 37 ... Engagement protrusion, 39 ... Rotating operation shaft.

Claims (2)

[Scope of utility model registration request] 1. A plurality of large-diameter double-fastening bolts each having a central through hole in a horizontal flange of an object to be fastened, and a heavy upper nut and a lower nut screwed to upper and lower screw portions of the respective double-fastening bolts. It is a device for removing and attaching the lower nut, which is dangerous to remove and install the nut of the bolt when repairing and inspecting equipment that is fastened and connected with the built-in telescopic working cylinder. A post that can be expanded and contracted in the vertical direction by the operation of the cylinder and a hook pin that can be inserted into the upper portion of the center through hole of the bolt are attached to the upper end of the post so that the post is located near the bolt to be attached and detached. And a post suspension arm for vertically suspending the post and a model for holding the post in a vertical suspension posture by being provided at an intermediate position in the height direction of the post and contacting the tip end with the outer peripheral end face of the flange. Attachment stopper, a revolving column fixed to the lower end of the telescopic actuating tube of the post, a telescopic column inserted into and retained by the revolving column so as to be able to move back and forth in the horizontal direction, and engageable with and disengageable from the end face groove of the lower nut. A weight nut attaching / detaching device comprising a nut attachment having a possible engaging projection and rotatably supported on the tip of the telescopic column. 2. A telescopic working cylinder built into the post is an air cylinder with a lock brake, and a weight nut up to 3 inches to 7 inches is moved up and down by operating a control box capable of adjusting air pressure. The weight nut attaching / detaching device according to claim 1, which is configured to be stopped at an arbitrary position.